In this paper, a novel exemplar-based completion model which is used to remove
objects from natural image and texture image is proposed. Firstly the model selects a
dynamic size of exemplar based on the local texture information. Secondly, the filling
order of exemplar is determined by a cross-isophote diffusion data item. The data item is
the result of partial differential equation (PDE) which is derived based on the geometrical
property. It considers the extent of edge, so it has a good linear structure preserving
property. Thirdly, when processing the textured image, both color and gradient information
is incorporated into the similarity function, and then the right texture patterns are
preserved. Lastly, a gradient constrained total variation (TV) interpolation is used to reduce
seams between exemplars in the completed image. Both theoretical analysis and
experiments are given to demonstrate the performance of our model.

Received May 17, 2007; revised September 4, 2007; accepted September 28, 2007.
Communicated by H. Y. Mark Liao.
* This paper was partially supported by the National Natural Science Foundation of China under grants No.
60472033, No. 60672062; the National Grand Fundamental Research 973 Program of China under grant No.
2004CB318005; and the Technological Innovation Fund of Excellent Doctorial Candidate of Beijing Jiaotong
University No. 48026.